Method of eliminating foam in paper manufacture



Patented May 5, 1931 UNITE DrSTATES PATENT OFFICE nAnoLD ROBERT RAITON, or LAwnrncE, MASSACHUSETTS, Assrenor. To RAFIOLD rnoonss CORPORATION, A conroaATIoN or MASSACHUSETTS METHOD or ELIMINATING FOAM m PAPER MANUFACTURE No Drawing.

This invention relates to and has for its principal object a method for the reduction, elimination, prevention, or alteration of foam in themanufacture of a substantially unsized carbonate filled paper.

An important object of this invention is the improvement of machine operation, .particu-- larly as regards the dandy 'roll.

A further object is the improvement in 19 the quality of the paper produced.

Other objects and advantages of this invention will become apparent during th course of the following description.

In my copending application Serial #202,453 of June 29, 1927, I have disclosed a method for the reduction, elimination, prevention, or alteration of foam in some cases where carbonate fillers are used in paper making by the employment of starch or starch 20 and alum.

The present invention relates to a new method applicable under similar conditions, but is confined to the manufacture of substan; tially unsized carbonate filled .papers.

In some cases when carbonate fillers of the character hereinafter referredto are incorporated into a paper mix of a character suitable for preparing substantially unsized paper, and this mix is run off on a web-forming device, such as the screen of a Fourdrinier machine, a considerableamount of foam is produced during the process and. particularly at the wet end of the paper machine. If the mixin this condition is run on to the webforming device an excessive amount of foam will be present thereon with the result that an inferior grade of paper is produced. Sometimes, even if there is no important amountof foam apparent on the web as it islbeing formed on the wire, the stock seems to be of suchv a nature that foam is formed by the action of the dand as it rides on the web.

Moreover, I have ound that when running certain unsized stocks containmg carbonate fillers, particularly. stocks containing old papers, there is a'tendency for the dandy roll. to fill up which results after a time in its pick- I ing up pieces of the paper web with the result that the web is broken and. the dandy roll must be flushed out. Itwill beapparent Application filed Septemben 5, 1928. Serial No. 304,171.

that these disadvantageous features result in inconvenience and substantially reduced economy of the process. I

I have discovered that the'foam normally present or producible in paper stocks referred to above containing'carbonate filler which are used for preparing substantially unsized paper can be substantially reduced in amount if not completely eliminated, or can be altered in character so that the presence of the foam on the web-forming device is not objection-.

able, by treating the mix with a suitable agent such as alum at the Wet end of the paper machine, or preferably y addin a small amount of-sodium resinate and a lum to the mix while in the beater or similar machine or to the mixer or similar device where'a beater is not employed, and subsequently treating themix with an additional amount of a restoring agent such as alum at the wet end of the paper machine. The addition of alum alone to the stock in theconcentrated condition,-as in the beater, does not produce the desired efl'ect.

In the practice of my process wherein alum alone is employed, the alum is added preferably continuously, preferably in solution, to' the substantially unsized paper mix containing carbonate filler at or subsequent" to the point where the mix is diluted prior-to passing it on to aweb-forming device, i. eunder conditions favoring the minimizing of the time and/or intimacy of contact of the alum with the constituentsof the paper mix. The

amount of alum to be added will depend upon the character of the particular mix being treated. Ordinarily alum in an amount of from one half to two per cent. by w ight of the constituents of the mix considere on a air dry basis will be found to be satisfactory, but in some cases I have found that a lesser amount was satisfactory, while inothers a greater amount seemed to be necessary.

In the preferred practice of my process I add to a fi for use in manufacturing unsized paper,

rous mix of any character suitable.

while the mix is in the beater, a small amount carbonate filler. Whereas the carbonate filler m y be added to the fibrous mix originally,

of sodium resinate and alum. I then add the i my experiments indicate that subsequent addition of the carbonate filler is preferable. The amount of sodium resinate added is less than that amount which would produce a sub- 5 stantially sized paper. Although the action of the sodium resinate and alum is substantially deteriorated, sometimes even to the point of destruction, by the carbonate filler, I have discovered that the efiectiveness of these materials can be restored by treating the mix with a subsequent amount of alum preferably continuously, preferably in solution, at or subsequent to the point where the mix is diluted prlor to its passage on to a web-forming device, i. e. under conditions favoring the'minimizing of the time and/or intimacy of contact of the alum with the constituents of the paper mix. This restoration results in a substantial reduction, elimination or alteration of the foam produced in the mix by the carbonate filler and substantially eliminates the tendency of the dandy roll to be quickly filled up and to pick up pieces of the paper web.

An illustrative furnish suitable for use when alum alone is used at the wet end of the paper machine is as follows:

Material added to mix proportionately and continuously on dilution Pounds Alum 40 Another suitable furnish is Materials added in beater Pounds Fibrous furnish, e. g. approximately equal parts of sulphite and soda pulps 1644 Carbonate filler, e. g. calcium carbonate magnesium hydroxide 356 Material added to mid proportionately and continuously on dilution Pounds Alum 30 An illustrative furnish suitable for use when alum and sodium resinate are addedin the beater and a subsequent amount of alum added at the wet end of the paper machine is as follows:

Materials added in, beater Pounds Fibrous furnish, e. g. approximately equal parts of sulphite, soda, and old paper stocks 1644 Sodium resinate; 6

Material added to mix proportionately and continuously on dilution Pounds Fibrous furnish, e. g. approximately equal parts of sulphite and soda pulps 1644 Sodium resinate 6 Alum 1O Carbonate filler, e. g. calcium carbonate magnesium hydroxide 356 Material added to mid proportionately and continuously on dilution In the above formulae, the weights of sodium resinate and carbonate filler refer to the bone dry basis, the weights of the other ingredients being given on the air dry basis.

As is apparent from the foregoing, the primary object of my invention is to maintain the desired effect of a material such as alum in a paper mix containing carbonate fille'r,or to restore the eifect of the precipitates of a small amount of sodium resinate and alum in such a mix by the addition of a restoring agent such as alum. If alum were "added under conditions ordinarily obtaining in paper mixes, it would react chemicall with the carbonate filler and thus be destrloye However, I am able to obtain the desired effect of this alum in the paper mix by adjusting conditions under which the alum is added so as to substantially prevent it from reacting chemically with the carbonate filler. There is therefore substantially no conversion of the carbonate filler into a neutral compound by reaction with the alum added under these conditions, and the carbonate filler continues to exist in the mix. Whereas I have not limited myself to any definite amount of carbonate filler nor any definite amount of alum to be added under these conditions, the illustrative furnishes given herein indicate that normally the carbonate filler constitutes a substantial percentage of the total furnish and consequently of the paper produced, and that it is present in the furnish in an amount greatly in excess of the stoichiometrical equivalent of the alum thus added. Thus it will be noted that even were conditions such that reaction between the alum thus added and the carbonate filler could take place and go to completion, which is substantially not the case in my invention, the final result would not be a neutralization of the mix but rather a using up of this alum and the mix would remain on the alkaline side owing to the excess carbonate filler present. It is thus apparent that my process, in which a paper is produced containmg a substantial quantity Elli till) of carbonate filler, is wholly unrelated to any paper-making procedure wherein alum or the like is added toa paper mix for the purpose "of substantially neutralizing the same so that the final paper will contain substantially no alkaline constituents.

I have discovered that inplace of alum when used either originally in the beater or subsequently as a restoring agent I may use with a measure of success certain acidic materials such as sulphuric acid (H 80 or acid salts such as sodium bisulphate (NaI-ISO or other salts of aluminum. Of the aluminum salts available the chloride or the like, or the double salts which are the true alums, may be used, but because of economy I prefer to use the ordinary sulphate of aluninum, commonly called alum.

In place of sodium resinate I may employ other soaps, for example the oleates, or any other material derived by treatment with an alkaline substance or the like from material originally of acid characteristics or from other material which likewise is of a partly or completely saponifiable nature, such for example as saponified beeswax.

By the term carbonate filler as employed herein is intended to be included calcium carbonate, of which lime mud from the cansticizing process is one form; calcium carbonate magnesium basic carbonate employed in the paper disclosed in my U. S. Patent No.. 1,595,416; calcium carbonate magnesium hydroxide disclosed in my II. S. Patent No. 1,415,391; or other substantially water insoluble normal or basic carbonates of alkaline earth metals, -(which expression is herein intended to include magnesium), or compounds, or double salts, or physically associated mixtures of these with one or more other acid soluble materials of a substantially water insoluble nature. The term carbonate filler is also intended to include fibrous material and/or other material such as paper coating constituents or the like containin one or more compounds of the character aove referred to, such as old papers or similar papers, broke or the like.

By the term wet end of the pa er machine is intended to be included t ose instrumentalities provided in paper manufacture by which and/or in which a relatively concentrated paper mix is diluted, and treated, conveyed or fed up to the point of web formation, such as the mixing box, regulating and proportioning devices, rlfiers, troughs, screens, head boxes, inlets, and the like, including also instrumentalities used in the white water cycle.

Where I use the term sodium resinate it is to be understood that I mean it to include any material produced by the action of alkal i, generally in aqueous solution, on rosin, or on natural or synthetic resin acidor acids,

regardless of the exact composition of the.

product, or the varying composition which different samples may possess.

When I use the word paper herein, I use it in the broad sense to include products of manufacture of all types and of all weights and thicknesses, which contain as an essential constituent a considerable amount of prepared fibre and which are capable of being produced on a Fourdrinier, cylinder, or other forming, felting, shaping or molding machine.

In the claims, where I use the expression eliminating foam, I mean to include not only those cases in which the foam is wholly or almost wholly eliminated, but also those in'which the amount of foam formed is reduced, those in which the character of the foam is so changedthat it breaks with relative ease, those in which foam is prevented from forming, and also cases in which two or more of the above possibilities are operative.

While I have described in detail the preferred practice of my process it is to be un derstood that the details of procedure, the proportions of ingredients, and arrangement of steps may be widely varied without departing from the spirit of the invention or the scope of the subjoined claims,

I claim:

1. The method of manufacturing substantially unsized paper filled with carbonate filler comprising adding to a mix containing fibrous material and carbonate filler, acidic material at the wet end of the paper machine, and thereafter making'paper therefrom.

2. The method of manufacturing substantially unsized paper filled with carbonate fillercomprising adding to a mix containing fibrous material and carbonate filler, an aluminum saltat the wet end of the paper fibrous material and carbonate filler, which mix would normally reduce deleterious foam in the manufacture oipaper therefrom, which comprises adding alum to such mix at the wet end of the paper machine."

5. The method of eliminating foam in the manufacture of substantially unsized paper filled with carbonate filler comprising adding to fibrous material saponified material, acidic material, and carbonate filler, said saponified material being added in an amount insufiicient to produce a substantially sized paper, thereafter adding to the resulting storing agent at the wet end 0 the paper mix a remanufacture of substantiallyunsized paper filled with carbonate filler comprising adding to fibrous material saponified material, alum, and carbonate filler, said saponified material being added in an amount insuflicient to produce a substantially sized paper, thereafter adding to the mix a restoring agent at the wet end of the paper machine, and thereafter making paper therefrom.

8. The method of eliminating foam in the manufacture of substantially unsized pa er filled with carbonate filler comprising adding to fibrous material saponified material, alum, and carbonate filler, saidsaponified material being added in an amount insufficient to produce a substantially sized paper,

thereafter adding to the mix a salt of aluminum at the wet end of the paper machine,

and thereafter making paper therefrom.

9. The method of eliminating foam in the manufacture of substantially unsized paper filled with carbonate filler comprising adding to. fibrous material sodium resinate, alum, and carbonate filler, said sodium resinate being added in an amount insuflicient to produce a substantially sized paper, thereafter adding to the mix alum at the wet end of the paper machine, and thereafter making paper therefrom.

10. The method of eliminating foam in the manufacture of substantially unsized paper filled with carbonate filler comprising adding to fibrous material in a beater sodium resinate, alum, and carbonate filler, said sodium resinate being added in an amount insufficient to produce a substa-ntialy sized paper, thereafter adding to the mix alum at the wet end of the paper machine, and thereafter making paper therefrom.

11. The method of eliminating foam in the manufacture of substantially unsized paper filled with carbonate filler comprising adding to fibrous material sodium resinate, alum,

and carbonate filler comprising alkaline earth metal carbonate, said sodium resinate being added in an amount insuflicient to produce a substantially sized paper, thereafter adding to the mix alum at the wet end of the paper nachine, and thereafter making paper there- 12. The methodof eliminating foam in the manufacture of substantially unsized pa er filled with carbonate filler comprising a ding to fibrous material sodium resinate, alum, and carbonate filler comprising calcium carbonate, said sodium resinate being added in an amount insufiicient to produce a substantially sized paper, thereafter adding to the mix alum at the wet (and of the paper machine, and thereafter making paper therefrom.

13. The method of eliminating foam in the manufacture ofsubstantially unsized paper filled with carbonate filler comprising adding to fibrous materi al sodium resinate, alum, and carbonate filler comprising calcium carbonate and magnesium compound, said sodium resinate being added in an amount insufficient to produce a substantially sized paper, thereafter adding to the mix alui'n at the wet end of the paper machine, and thereafter making paper therefrom.

14. The method of eliminating foam in the manufacture of substantially unsized paper filled with carbonate filler comprising adding to fibrous material sodium resinate, alum, and carbonate filler comprising calcium carbonte magnesium hydroxide, said sodium resinate being added in an amount insufiicient to produce a substantially sizedpaper, thereafter'adding to the mix alum at the wet end of the paper machine, and thereafter making paper therefrom.

15. In a method of making substantially unsized paper filled with carbonate filler, the step of adding toa paper mix containing carbonate filler, an acidic material at the wet end of the paper machine.

16. In a method of making substantially unsized paper filler with carbonate filler, the

step of adding to a paper mix containing carbonate filler, a compound of aluminum at the wet end of the paper machine.

17 In a method of making substantially unsized paper filled with carbonate filler, the step of adding to a paper mix containing carbonate filler, alum at the wet end of the paper machine.

18. In a method of the character described, the step of adding to a paper mix comprising fibrous material, the reaction product of a small amount of sodium resinate and alum, and carbonate filler, said reaction product being present in an amount insufficient to produce a substantially sized paper and having had its effectiveness deteriorated by the carbonate filler, a restoring agent at the wet end of the paper machine. I

19. Ina method of the character described, the step of adding to a'paper mix. comprising fibrous material, the reaction product of a small amount of sodium resinate and alum, and carbonate filler, said reaction product being. present in an amount insufficient to produce a substantially sized paper and havlng had its effectiveness deteriorated by the car- Ill) bonate filler, alum at the wet end of the paper the manufacture ofpaper, and an aluminum compound.

21. Paper substantially unsized and substantially free from foam marks comprising paper ingredients including fibrous material and carbonate filler, which ingredients normally would produce deleterious foaming in the manufacture of paper, and the reaction product of a small amount of saponified material and acidic material.

22. Paper substantially unsized and sub- I stantially free from foam marks comprising paper ingredients including fibrous material and carbonate filler, which ingredients normally would produce deleterious foaming 1n the manufacture of paper, and the reaction product of'a small amount of sodium resinate and acidic material. I 23. Paper substantially unsized and substantially free from foam marks comprising paper ingredients including fibrous material and carbonate filler, which ingredients normally would produce deleterious foaming in the manufacture of paper, and the reaction product of a small amount of sodium resinate and a salt of aluminum.

24. Paper substantially unsized and substantially free from foam marks comprising paper ingredients including fibrous material and carbonate filler, which ingredients normally would produce deleterious foaming in the manufacture of paper, and the reaction product of a small amount of sodium resinate and alum.

25. Paper substantially unsized and substantially free from foam marks comprising paper ingredients including fibrous mate rial and carbonate filler comprising alkaline earth metal carbonate, which ingredients nor- 'mally would produce deleterious foaming in the manufacture of paper, and the reaction product of a small amount of sodium resinate and alum. r

26. Paper substantially unsized and substanti ally free from'foam marks comprising paper ingredients including fibrous material I and carbonate filler comprising calcium carbonate, which ingredients normally would produce deleterious foaming in the manufacture of paper, and the reaction product of a small amount of sodium resinate and alum. 27 Paper substantially unsized and substantially free from foam marks comprising paper ingredients including fibrous material and carbonte filler comprising calcium car bonate and magnesium compound, which ingredients normally would produce deleterious foaming in the manufacture of paper,

and the reaction product of a small amount of sodium resinate and alum.

28. Paper substantially unsized and substantially free from foam marks comprising paper ingredients including fibrous material and carbonate filler comprising calcium car-v bonate magnesium hydroxide, which ingrethe reaction product of'a smallamount of so dium resinate and alum. I

29. Paper substantially unsized. and substantlally free from foam marks comprising paper ingredients including fibrous material," of which at least a part is old paper stock, and carbonate filler, which ingredients nor-' mally would produce deleterious foaming in the manufacture of paper, and an aluminum compound.

30. The method of manufacturing substantially unsized paper filled with carbonate filler comprising adding to a mix containing fibrous material and carbonate filler a compound of aluminum at the wet end of the paper machine, and thereafter making paper therefrom.

31. The method of producing substantially unsized paper filled with carbonate filler, comprising adding a metallic salt at the wet end of the paper machine to a paper mix containing carbonate filler, and thereafter making paper therefrom.

82. The method of producing substantially unsized paper filled with carbonate filler, comprising adding a metallic salt at the wet end of the paper machine to a paper mix containing carbonate filler comprising alka line earth metal compound, and thereafter making paper therefrom.

end of the paper machine to a paper mix containing carbonate filler comprising calcium carbonate, and thereafter making paper therefrom.

'34. The method of producing "substantially unsized "paper filled with carbonate filler, comprising adding a metallic salt at the wet end of the paper machine to a paper mix containing carbonate filler comprising calcium carbonate and magnesium compound, and thereafter making paper therefrom.

35. The method of producing substantially unsized paper filled with carbonate filler, comprising adding a metallic salt at the wet end of the paper machine to a paper mix containing carbonate filler comprising calcium carbonate magnesium hydroxide, and thereafter making paper therefrom.

In testimony whereofI aflix my signature.

HAROLD ROBERT RAFTON. 

